The inventor herein was the inventor in the matter of the Australian Pat. Nos. 432,124 and 434,936 standing in the name of Jury & Spiers Proprietary Limited, and Australian Pat. No. 500,092 standing in the name of Ampliform Pty. Ltd. In all of those patents, there was disclosed a product formed by the process of extruding an aluminium workpiece, slotting the workpiece and expanding it. In the first two said patents, the workpiece was flanked on each side with webs which formed the upper and lower chords of a beam, while in the third patent, the chords were absent so that the workpiece was expanded without the limitations imparted by the chords, and therefore the expansion could be increased. This further feature has proved to be commercially valuable.
One of the difficulties which was encountered with the truss-like metal member referred to in the first two said Australian patents was the limitation of the angle to which the struts could be stretched, and this was found to be insufficient to provide a useful viable truss which was competitive with certain other trusses which are available. A limitation encountered with the mesh-like member was that it had little dimensional stability, and it was not suitable, for example, for use as a load-bearing panel. Furthermore, the openings were such that the mesh-like member could sometimes be used as a ladder, for example by a child, and an accident hazard could possibly result.
The main object of this invention is to provide improvements whereby expanded metal can have additional members fabricated therein which will impart considerable strength providing load-bearing characteristics in at least one direction in one plane, and which will also reduce the opening size and thereby limit the likelihood of use in a ladder mode.